Abstract: A white light emitting device with an efficiency of at least 230 lm/W at a blue LED chip input current density from 10 to 60 mA/mm2, preferably in the range from 15 to 40 mA/mm2 and more preferably in the range from 20 to 30 mA/mm2. The device comprises a substrate, at least one string of blue LED chips mounted on the substrate and a phosphor material composition. Said phosphor material composition comprises a narrow band red phosphor which generates light with a peak emission wavelength in a range from 625 nm to 635 nm. The weight percentages of the narrow band red phosphor are between 33 to 49 wt. % for a CCT of from 4000 to 6500K or in an amount of from 60 to 70 wt. % for a CCT of from 2700 to 3500K CCT.

Abstract: A lighting device (1) is disclosed comprising a transmissive housing (3) and a filament (10) within said transmissive housing. The filament comprises a transmissive substrate (20) carrying a plurality of solid state lighting elements (30) and a phosphor containing resin coating (40) enveloping said filament. The resin coating includes at least one region (42) leaking light produced by said solid state lighting elements that is unconverted by said phosphor and the transmissive housing carries a further phosphor layer (7) covering part of the transmissive housing for each of said regions of the resin coating, each of said further phosphor layers being arranged to receive said unconverted light leaking from at least one of said regions. Also disclosed is a method of manufacturing such a lighting device.

Abstract: A lighting device (1) is disclosed comprising a transmissive housing (3) and a filament (10) within said transmissive housing. The filament comprises a transmissive substrate (20) carrying a plurality of solid state lighting elements (30) and a phosphor containing resin coating (40) enveloping said filament. The resin coating includes at least one region (42) leaking light produced by said solid state lighting elements that is unconverted by said phosphor and the transmissive housing carries a further phosphor layer (7) covering part of the transmissive housing for each of said regions of the resin coating, each of said further phosphor layers being arranged to receive said unconverted light leaking from at least one of said regions. Also disclosed is a method of manufacturing such a lighting device.